Most common cause of Thrombotic Pulmonary Embolism is

(B) Deep vein thrombosis# DEEP VENOUS THROMBOSIS in the leg or in the pelvis is most likely the cause of pulmonary embolism, but in about 80-90%, it occurs without any previous clinical manifestations.> Pulmonary embolism: Following dislodgement of venous thrombi generally from femoral and iliac veins.> Causes: Multiple trauma, tumor embolus, amniotic fluid.> Sign and symptoms: Pleurisy, haemoptysis, crackles, shortness of breath.> Sign and symptoms of right heat failure and raised CVP> Diagnosis: Ventilation perfusion scan (confirm the diagnosis). Contrast enhanced CT scan (most accurate technique).> Treatment: Thrombolytic agents (streptokinase, TP factors).> Pulmonary embolectomy (may be required).> Lung transplantations indicated in: End stage parenchymal or pulmonary vascular disease> Cystic fibrosis and irreversible pulmonary hypertension with right ventricular failure.